Luxurious and functional windows/doors of buildings have been developed in various forms for use. These include lift-sliding type system windows/doors which have been widely applied to relatively large windows/doors of living rooms or balconies, and security windows/doors having security functions.
Windows/doors used in many different buildings essentially include window/door frames to be connected with windows/doors to be opened/closed by a sliding motion. These windows/doors need to be weatherproof having high resistance to the outside air, durability and high mechanical properties to bear the load of glass.
In the conventional window/door system, a window/door frame includes a rail groove to be connected with a window/door to be opened/closed by a sliding motion. However, when people walk passing the rail groove, the rail grove causes a feeling of irritation to the feet or acts as a dangerous obstruction causing them to stumble. Further, in the window/door frame used in verandas, foreign substances including dust easily collect in the rail groove and it is difficult to clean and remove the foreign substances from the rail groove. Specifically, since a draft or rainwater easily comes into through the window/door frame used in the verandas and the rail groove thereof, air tightness and drainage are greatly reduced.
To solve the above-indicated drawbacks, a window/door having a hidden rail structure that does not expose the rail groove and improves air tightness and drainage has been launched. However, since a structure combining a window/door with a rail groove of a window/door frame is complicated, it is very difficult to separate the window/door from the rail groove. In addition, since no structure to drain rainwater is separately provided, drainage is not good. Moreover, since the structure to block a draft is simple, it fails to thoroughly block the draft from passing through.
Furthermore, in the conventional window/door having a hidden rail structure like a general window/door, heat or cold air from the outside is transmitted to the inside by the metal frame. Accordingly, a thermal loss by the heat conduction still occurs.
To solve the problems of the conventional art, the applicant of the present invention filed a patent application for a composite window/door apparatus using different frame materials and registered it as a patent (Korean Patent Registration No. 10-1302093).
The conventional composite window/door apparatus comprises a window frame using different materials and a sash frame using different materials.
The window frame using different materials comprises a first window frame made of synthetic resin and a second window frame made of metal. The first window frame forms a part of the window frame and it is to be positioned in an inside window frame installation space of a window frame installation space. The second window frame forms the rest window frame and it is to be positioned in an outside window frame installation space of the window frame installation space.
The sash frame using different materials comprises a first sash frame made of synthetic resin and a second sash frame made of metal, which form a sash frame of interior and exterior window glass. The first sash frame forms a part of an inside sash frame and is positioned inside. The second sash frame forms the rest of the sash frame and it is positioned outside to be connected with the first sash frame.
That is, the parts of the window frame and the sash frame to be positioned outside include the second window frame and second sash frame made of metal. The rest of the window frame and sash frame to be positioned inside include the first window frame and first sash frame made of synthetic resin to block heat conduction between the second window frame and second sash frame made of metal and inside.
However, the conventional composite window/door apparatus has a drawback: It is troublesome to connect the first window frame made of synthetic resin with the second window frame made of metal and to connect the first sash frame made of synthetic resin with the second sash frame made of metal. That is, after the first window frame and second window frame made of different materials are fit into each other and the first sash frame and second sash frame made of different materials are fit into each other, since an adhesive agent is applied or locking bolts are used to connect those frames together, assembling work is troublesome. Moreover, a sense of beauty on the frames using different materials lowers by the area where the adhesive agent is applied or the locking bolts are tightened.
The conventional composite window/door apparatus has another drawback in connecting the frames made of synthetic resin.
In the conventional composite window/door apparatus, the first window frames made of synthetic resin are connected together and the first sash frame made of synthetic resin are connected together by a heat-sealing method or an attaching method using an adhesive agent.
The heat-sealing method of the synthetic resin frames in the conventional composite window/door apparatus is as follows: The first window frame and first sash frame made of synthetic resin are cut, at an angle of 45 degrees, in their respective ends. To connect ends of the first window frames together and to connect ends of the first sash frame, the corresponding ends thereof are heated to be bonded together. Then, a bonded area which protrudes is cut to be flat by heating and pressurizing.
Additionally, the connecting method using an adhesive agent in the conventional composite window/door apparatus is as follows: To connect the ends of the first window frames made of synthetic resin together and to connect the ends of the first sash frames made of synthetic resin, these ends being cut at an angle of 45 degrees, an adhesive agent is applied to the corresponding ends of the frames to be connected together. After gluing the two ends where the adhesive agent is applied, it needs time to wait until the ends are completely glued together. Then, the adhesive agent outwardly protruding from the glued area is cut to make the outer surface of the connected area smooth.
However, the aforementioned heat-sealing method or attaching method using an adhesive agent to connect the synthetic resin frames has the problems in that: since the work process is troublesome, working time is delayed and labor cost is increased; since the glued area is not neat, the appearance beauty of the composite window/door apparatus is damaged; and the glued area easily loosens or deteriorates.